$\lim_{x\to\infty}\left(\frac{tan\left(2x\right)}{ln\left(x+1\right)}\right)$

$\int_1^2\left(-\frac{4x}{y}\right)dy$

$36-4w=8w$

$10-\left(1-\sqrt{2}\right)i$

$\frac{d}{dx}\left(x^2-4xy+4y^2+4x-3y-7=0\right)$

$\left(25:-5\right)$

$\left\{70-\left[40-\left(-50+30\right)-30\right]\right\}-20$